gecko-dev/toolkit/content/viewZoomOverlay.js

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JavaScript

# -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
#
# ***** BEGIN LICENSE BLOCK *****
# Version: MPL 1.1/GPL 2.0/LGPL 2.1
#
# The contents of this file are subject to the Mozilla Public License Version
# 1.1 (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
# http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
# for the specific language governing rights and limitations under the
# License.
#
# The Original Code is this file as it was released upon January 6, 2001.
#
# The Initial Developer of the Original Code is
# Peter Annema.
# Portions created by the Initial Developer are Copyright (C) 2000
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
# Peter Annema <disttsc@bart.nl> (Original Author)
# Jonas Sicking <sicking@bigfoot.com>
# Jason Barnabe <jason_barnabe@fastmail.fm>
#
# Alternatively, the contents of this file may be used under the terms of
# either the GNU General Public License Version 2 or later (the "GPL"), or
# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
# in which case the provisions of the GPL or the LGPL are applicable instead
# of those above. If you wish to allow use of your version of this file only
# under the terms of either the GPL or the LGPL, and not to allow others to
# use your version of this file under the terms of the MPL, indicate your
# decision by deleting the provisions above and replace them with the notice
# and other provisions required by the GPL or the LGPL. If you do not delete
# the provisions above, a recipient may use your version of this file under
# the terms of any one of the MPL, the GPL or the LGPL.
#
# ***** END LICENSE BLOCK *****
/** Document Zoom Management Code
*
* To use this, you'll need to have a getBrowser() function.
*
**/
function ZoomManager() {
}
ZoomManager.prototype = {
instance : null,
getInstance : function() {
if (!ZoomManager.prototype.instance)
ZoomManager.prototype.instance = new ZoomManager();
return ZoomManager.prototype.instance;
},
MIN : 1,
MAX : 2000,
factorOther : 300,
factorAnchor : 300,
zoomFactors: [50, 75, 90, 100, 120, 150, 200],
steps : 0,
get textZoom() {
var currentZoom;
try {
currentZoom = Math.round(this.markupDocumentViewer.textZoom * 100);
if (this.indexOf(currentZoom) == -1) {
if (currentZoom != this.factorOther) {
this.factorOther = currentZoom;
this.factorAnchor = this.factorOther;
}
}
} catch (e) {
currentZoom = 100;
}
return currentZoom;
},
set textZoom(aZoom) {
if (aZoom < this.MIN || aZoom > this.MAX)
throw Components.results.NS_ERROR_INVALID_ARG;
this.markupDocumentViewer.textZoom = aZoom / 100;
},
enlarge : function() {
this.jump(1);
},
reduce : function() {
this.jump(-1);
},
reset : function() {
this.textZoom = 100;
},
indexOf : function(aZoom) {
var index = -1;
if (this.isZoomInRange(aZoom)) {
index = this.zoomFactors.length - 1;
while (index >= 0 && this.zoomFactors[index] != aZoom)
--index;
}
return index;
},
/***** internal helper functions below here *****/
isZoomInRange : function(aZoom) {
return (aZoom >= this.zoomFactors[0] && aZoom <= this.zoomFactors[this.zoomFactors.length - 1]);
},
jump : function(aDirection) {
if (aDirection != -1 && aDirection != 1)
throw Components.results.NS_ERROR_INVALID_ARG;
var currentZoom = this.textZoom;
var insertIndex = -1;
const stepFactor = 1.5;
// temporarily add factorOther to list
if (this.isZoomInRange(this.factorOther)) {
insertIndex = 0;
while (this.zoomFactors[insertIndex] < this.factorOther)
++insertIndex;
if (this.zoomFactors[insertIndex] != this.factorOther)
this.zoomFactors.splice(insertIndex, 0, this.factorOther);
}
var factor;
var done = false;
if (this.isZoomInRange(currentZoom)) {
var index = this.indexOf(currentZoom);
if (aDirection == -1 && index == 0 ||
aDirection == 1 && index == this.zoomFactors.length - 1) {
this.steps = 0;
this.factorAnchor = this.zoomFactors[index];
} else {
factor = this.zoomFactors[index + aDirection];
done = true;
}
}
if (!done) {
this.steps += aDirection;
factor = this.factorAnchor * Math.pow(stepFactor, this.steps);
if (factor < this.MIN || factor > this.MAX) {
this.steps -= aDirection;
factor = this.factorAnchor * Math.pow(stepFactor, this.steps);
}
factor = Math.round(factor);
if (this.isZoomInRange(factor))
factor = this.snap(factor);
else
this.factorOther = factor;
}
if (insertIndex != -1)
this.zoomFactors.splice(insertIndex, 1);
this.textZoom = factor;
},
snap : function(aZoom) {
if (this.isZoomInRange(aZoom)) {
var level = 0;
while (this.zoomFactors[level + 1] < aZoom)
++level;
// if aZoom closer to [level + 1] than [level], snap to [level + 1]
if ((this.zoomFactors[level + 1] - aZoom) < (aZoom - this.zoomFactors[level]))
++level;
aZoom = this.zoomFactors[level];
}
return aZoom;
},
get markupDocumentViewer() {
return getBrowser().markupDocumentViewer;
}
}